If I was going to use an aluminum support on the street, I would use less preload because of the thermal expansion difference, on new bearings around 10-15inlbs.
I have seen the unusual contact pattern on almost new races located over oil channel recesses in the race bore in certain applications, like the 8.25 and 9.25 Chrysler. I dont think it causes a problem. To me it does indicate that the race is not loaded uniformly due to the housing strength, which does not seem to be true in your application. Maybe the bore is out of round? but that seems unlikely.
Maybe you need to run your chunk in someone else's car? Or, borrow a chunk know to be quiet. Maybe the al case and your combination of suspension links is just prone to noise transfer.